NAME
Hash::Merge::Simple - Recursively merge two or more hashes, simply
VERSION
version 0.051
SYNOPSIS
use Hash::Merge::Simple qw/ merge /;
my $a = { a => 1 };
my $b = { a => 100, b => 2};
# Merge with righthand hash taking precedence
my $c = merge $a, $b;
# $c is { a => 100, b => 2 } ... Note: a => 100 has overridden => 1
# Also, merge will take care to recursively merge any subordinate hashes found
my $a = { a => 1, c => 3, d => { i => 2 }, r => {} };
my $b = { b => 2, a => 100, d => { l => 4 } };
my $c = merge $a, $b;
# $c is { a => 100, b => 2, c => 3, d => { i => 2, l => 4 }, r => {} }
# You can also merge more than two hashes at the same time
# The precedence increases from left to right (the rightmost has the most precedence)
my $everything = merge $this, $that, $mine, $yours, $kitchen_sink, ...;
DESCRIPTION
Hash::Merge::Simple will recursively merge two or more hashes and return
the result as a new hash reference. The merge function will descend and
merge hashes that exist under the same node in both the left and right
hash, but doesn't attempt to combine arrays, objects, scalars, or
anything else. The rightmost hash also takes precedence, replacing
whatever was in the left hash if a conflict occurs.
This code was pretty much taken straight from Catalyst::Utils, and
modified to handle more than 2 hashes at the same time.
USAGE
Hash::Merge::Simple->merge( , , , ..., )
Hash::Merge::Simple::merge( , , , ..., )
Merge through , with the nth-most (rightmost) hash taking
precedence.
Returns a new hash reference representing the merge.
NOTE: The code does not currently check for cycles, so infinite loops
are possible:
my $a = {};
$a->{b} = $a;
merge $a, $a;
NOTE: If you want to avoid giving/receiving side effects with the merged
result, use "clone_merge" or "dclone_merge" An example of this problem
(thanks Uri):
my $left = { a => { b => 2 } } ;
my $right = { c => 4 } ;
my $result = merge( $left, $right ) ;
$left->{a}{b} = 3 ;
$left->{a}{d} = 5 ;
# $result->{a}{b} == 3 !
# $result->{a}{d} == 5 !
Hash::Merge::Simple->clone_merge( , , , ..., )
Hash::Merge::Simple::clone_merge( , , , ..., )
Perform a merge, clone the merge, and return the result
This is useful in cases where you need to ensure that the result can be
tweaked without fear of giving/receiving any side effects
This method will use Clone to do the cloning
Hash::Merge::Simple->dclone_merge( , , , ..., )
Hash::Merge::Simple::dclone_merge( , , , ..., )
Perform a merge, clone the merge, and return the result
This is useful in cases where you need to ensure that the result can be
tweaked without fear of giving/receiving any side effects
This method will use Storable (dclone) to do the cloning
SEE ALSO
Hash::Merge
Catalyst::Utils
Clone
Storable
ACKNOWLEDGEMENTS
This code was pretty much taken directly from Catalyst::Utils:
Sebastian Riedel "sri@cpan.org"
Yuval Kogman "nothingmuch@woobling.org"
AUTHOR
Robert Krimen
COPYRIGHT AND LICENSE
This software is copyright (c) 2010 by Robert Krimen.
This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.